SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c163ea010912609d5c3f10d0283be7e35ed66f2d9b2c5fc3126898b55335fe5' 
  AND token = 'mV/V54skQItxyhKdwwWAu74hfFBZpHjM/HbLLwExGwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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