SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fd81c7c9fb826fdc53f0097bf33b25aaac5af549e116a397395eba4e53214367' 
  AND token = 'ZGildSBwWEjMTu4Nc7hx4tURFqXvrIVVQ6/4wDMumRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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