SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b5b083e57f7108623e96cacb304ec50ea9cb499a1b46b861b9d7beb169f76b6' 
  AND token = 'W2SWL4UpJ3hNYz13pW6jMBqAnmSVGwvh+oO9lHDl/uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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