SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4e2dc94b80d460d9b502fcb9a1777faba02970fbbaa2c93688dbec33eba0131' 
  AND token = 'kdLqC55LImWJvLdQZAOIx7OSb+iwgK3FWJWb0wcHCiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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