SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '964c675a20392c794783a2e473a09a684985973fd7e5008cca751073d8ab1fc0' 
  AND token = 'fS93L60wE21YkbiBj6CKHy+YG/KLBY/bFb1qxildg0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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