SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d2613d1322d10d8eddefaf4e83bce4d634aa3be23239d1e7bb2d70c94643130' 
  AND token = 'bbcNnVWjkIge0BVeWVdp6BE+SpDSbMB1uEdsLIxAyH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}