SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985827e31ebbd4ea2b35ce53b6dcd1b17450252de801f5cc8c59bd9179d48aae' 
  AND token = 'kgMFKtpyBJId4TbdGEOEPgIGlCYkv/IqpNGVEPxMbTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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