SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001a3997fb430f921516f740007211043f740a59aa2d872c4184c889f8e31c5d' 
  AND token = 'gqmTg+JI6xxjQ2dBaKKwTVCVqGUH2chYi54C+vbTkbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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