SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '867a77779717e3d0e2d6860eec7d9e780d18eae0dfe7cfede8827ee37acab038' 
  AND token = 'zYCr+UwMNYRnZSjILL9Dsx2cEIXwEM6h7HPbQg1wZos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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