SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '68c1fd8316c86d421111f6b4b82af6ac7272752ba04502ac5c24f5646ad5acd0' 
  AND token = 'k476VnnhZYpp6ZRTaxc8PyCEhX53EiR+u+ya0E7ghl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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