SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ac022e705a5291098c370d00a72a184c93f606643be78b6fd51f17ab2e4c7a5' 
  AND token = 'WsPJgQ8nziThVy4Xxfb+kUkYCxodGFwBUamrevSepZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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