SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8efe871b2e3fe09abfe6b303e7960c588707432d2c47fa75ceaa9a9e33985705' 
  AND token = 'xBlwlYsEVgq20kn/2fGlocnXB05Q42uG2TpfGLMWLp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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