SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bf0b65f17a30c79c05acd6925e902f9f877c45c0ec6a79375143f8530ac31781' 
  AND token = 'COPGxZPXbVDPSx75WgQ2q6TDegC/YG2tp0iazO5FmRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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