SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dccd64bc89971c181cb73d0b8e7e612c2aa7db9807ea21b117dc4c521be53cda' 
  AND token = '3YGqAOMiI6kxy1WMotKdxsgKBz/jtWLgfDYD2fLZbec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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