SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5db1c4310456c86bb18cffe0c8d88abecab880346df3f8d96ed86090dd51ab06' 
  AND token = 'lKPE/Y9sXyL2Vp44wwz3+iFwUJBODhNqlS4AbnUSIHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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