SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '202e3eeda49ce1558a8234643b6a8204202c573419d563a7ed5412528040bf1b' 
  AND token = 'x1OwWyKQAKdFtPMzRewgifYY9Sy43Y51Y5PYJhfVPyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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