SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a0253d10d9336fe5afdf3573a24e35a3153f615b469db7087ce45fb361dc89b' 
  AND token = 'j904sgZqQRtAZb/6GBeSP+T+ArK/XZiNo9SgRhS2c38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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