SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '577aebdb37734af110235d6b605c9b10c845c700306644a5e7a6b6646be82b57' 
  AND token = 'wB09A96iCDFj9J8STqUeJqeXemAQw3kCiiD4dpiUGGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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