SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be239bc720e58c4664ce4818dedccef24ce4fce22a83886871707706fa07f162' 
  AND token = 'f4HTV8lAQGyFuYW7PNU39TNBQIpNeeMkJ3NwcN39hgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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