SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e4c29ca63cd9749ba56ecd35908c706597b983ed0fe03da9aeefc0bc7175b4c' 
  AND token = 'LMZxspQ8U2pOLVNy6EGMIwMpW8BuNtAQpRadP7vIdGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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