SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8041826c4c18298058f858764db8f5e6c63fac435cb5543d5ab557a329bf6ae1' 
  AND token = 'Bb/qLxGDbChb/T1JTfCiQCzfvhwr8iv9Ckgjd5Fvsf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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