SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bf1c841083c830ab2479db665fa3713c3d424f339f533079ab16455ef5924fe' 
  AND token = 'A6uzbfe7w+RE9RapkNY0EqbYevIU4T/q0BcvRF8X9xE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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