SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1db1681412fd63f629610a01169cc070586dc1554b20de09ede238c790ed8f8c' 
  AND token = '4B7YSGiTxgQIKjqGsfRbPFeXOK8FEMImlVZ46glzpOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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