SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18d1f626084b4d07a3e4047e65c959cb5de09b5e18ed0b93d8c366cac063f6d1' 
  AND token = 'Fnje/78ML/QF6af7XCaGMw3dl4FfXPdWDRjn43kf8gk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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