SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9c4d09b2071b56dacd3d4d1a08bf4e1b1b3e286143099ffeaf71b4b5d633aa37' 
  AND token = 'tm4BFqGMmmml/aaejYlXdZ41SKkd+d0QB3MY5Svl+rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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