SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '570252b05255d28faa617a2c6d11e70a725a624c87524cb99da38f94a23f5f3e' 
  AND token = 'vKwXliDTz5lJuDqDN5rtWa6zHR9cDGncTd/yKILb0BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}