SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2a5bdafee19b6be57a697148978c731f0daa8bbf102bab460d6191604633300' 
  AND token = 'uIbwQDIyvzND4EgLqua9SIJHHThZVzNdLAgE4O1BP6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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