SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27c4de438f8bafcbe54ceb072ee965b8a3fc477842bfb0445d4ff9f9e1114a22' 
  AND token = 'MXarXpelT+f7xNEqDCaDvVZPMJIuSaxHBRN0dwHe8No=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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