SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f226ba798caa548f6527945456c78bc81cebda18069de4c23dc4d72563f9a4d6' 
  AND token = 'PQTFymBvryGsctxR6GrxD3Kem1wy1xYfG/tQfcsuoi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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