SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce954244894cb9a9a996ff19eb80fb8ddba6471c62c8bfa122ce1d58fbb9a707' 
  AND token = 'iAahn2AjhvEDhkU+CKROmenzD/V4X91NRLagVD+IeEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00124

JSON explain

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