SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84ad4d7bbde083b73b0440601801f9a86eafe3af122b2b6d1dc6a22c92fd340c' 
  AND token = '8covaOWD4TyNV6OldSKGRyVmEPvpSUqQO90CRD1H6ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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