SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aebf41d649b555337026173b9040bb322648560fb55d78f940d94af3f66ef8e' 
  AND token = 'Fd82JgY4ilG75bL2U9waBdqinDSVgKlCLVnMPmp2CMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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