SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9b404cda80ccf655cc7bbf62e9fa5f7195871aa2f6cb2d840cb3b9d8b665cb7' 
  AND token = 'quyjSvidkVYFPUNP4N7z13MA0eNOfmP4m/VDvfcrHXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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