SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2879ed877e934a9fcc4e0ed4586d72e4f744d22c796af20d959f3ce82d26b39' 
  AND token = 'AVEUemRLqwqP0ABp6I5IsCI+TGkRWtWrcn1ynBVSCH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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