SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '652dfbc3fb3cb1058129d07800404f074250b410f826671b384b96095b53e524' 
  AND token = 'JcH146HNwHC21cfxNr9mpc1WCKkDDc6diVDA+R7sg04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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