SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '428e1bc9cccb6753f19e4ccebbb76608556678a0ff6871853789de185ce7e07b' 
  AND token = 'uZsR7N+R3zDYL9B4aPt/VlReOlCwC98yHPw8nvMjhdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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