SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e2dd0d6f51d7f657869c5b80f0f0a977a49b3b2ee1e14522b1a6f38660630f' 
  AND token = 'rDSNLGrm5obVoI5v/zTYYNga5tkTXl4c3mFPkqrj7XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}