SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1f758c75301a25ebcbca7eea72f11c1b6810cc889f6193aba726b58cf6e00d0' 
  AND token = 'yOmrZYMlUqaKkRQCiQewomIBKY02B7fp7Sk0tIE/fJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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