SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b03daa24d9e49f2466dffa81ee0ac5ff99c7758ea01313c5b31f06ab798e4d9' 
  AND token = 'zQ72WGZNp+ZxLXPwluILRjZwM3PJ9NLqiKTbSldfmw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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