SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd0221922474538fa8478f298ec23ce6e781e4e16566ed186af698dec2a234f8' 
  AND token = 'P/N+vnQ1/QONIghyBQ4yowSjTm/bxvhzuiWY5+lmCm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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