SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f660b89c933ddbd309049917a6b91642f65997e64328d41d6cba92fc8b9c8cb' 
  AND token = 'CZN/nO/ekFN4KVkJ7kxjViiStTPdHPv9CM8ztP6dSnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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