SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd362dca01edad2b82ffd716fa7154b1800ae0358634547a57ac72cf323498e0' 
  AND token = 'oamKexSx459OtogkPXdhYIX/rRU95pO84EIgvzfmMbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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