SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4454e738b9257244cc35c07f8c7904197fae013c2c8e10f89819c61b4c046bb1' 
  AND token = 'eCHu+NilvXn9poCBJwHY8iBvg6+VaIVz8yaqDB1za2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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