SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd25da38081163b90167f0c891fb5a34a2c9dca2601caff1c97445666be83245b' 
  AND token = 'bQ/rLADVmYGBEvQ99/yYNCEFAwN0/NhnMpEt/sOq7/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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