SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c5642fd38a338857307656de70fba257cb5bff6d5750d0e42dc35fbe5ceae28b' 
  AND token = 'rc950ywUNRpxIdETxkYjZcc5rwAjV7cGflTAAeb8Yfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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