SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '024702b4017daa97f2db396a0731d4ad31cac5c876922399badda0a8ec28877e' 
  AND token = 'ZFqr76bKYXbHjdXCw8AVHlDYw63glz0+83+fKiGWuVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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