SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7627c847f36551558cf74a9dc275fd52c77ac67b1f76edd69b4655545f38e5af' 
  AND token = 'i+AIOsFT5gbZKtP1z3aWAcTNbSX0FR0qaa5OkVKmS5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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