SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96fe6bd4a2700c4a7a6f86bb11dd7c3ead2ee1675f806f1f946fb741fc48d64b' 
  AND token = 'tEyYZU2Un7yX/Af0wo37lXeVB2mE4jWt32M+VlpEDaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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