Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '51b75a2b8cdf7f664aefba031dc441ca2bdd0fdbdd8b9be3ffe741af0d714990' 
  AND token = '9QcoqfRDrqVBacEjUeVgkAkxCEmA8pJieo9k7khhfSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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