SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da78d05dbb1d0729fcab9771163184051d890d4a2514b4c24047e31ab7e2c609' 
  AND token = 'nCGhEYOTxv+3h0d10xIQpr9Enqs5blXXlJ41RQoSSL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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