SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42cffa3bcc2d0db9c66f23c2cbd36edbc6a273b191367ae84944243d86d950dc' 
  AND token = 'poklFgnxvphdU6OGA5xwWejFLuYr2Q0agJh+UNGnONw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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