SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a669ce49d753639e1f2f9503eb96906545e69decaeb9ad424ad1c97fe987e994' 
  AND token = 'O6lfUnBJ9KUVKspefp2822xwIYNpa6tjTl9EMSsC+Bo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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