Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83493e308171806c18f3b7178caab2c6951f3a2abe097c1ce844e5d44199de2a' 
  AND token = 'y07FFdgysIsAPm6XSAFePprsLmIzMuOBd3AvgICTBqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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