SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75f5ba999b4329e6f8c4e1809de81a2ea1b86ba17913f4320ed2ab636a121a8b' 
  AND token = 'YvlRRC20gAS2FQC4VxlJsbKU/SBKxCYHGExK9mBbdqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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