SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46572da0f7065d936e9b16895a78222a397fe646a8d8271cf234f02823578dfc' 
  AND token = 'WsByxoOC+sjGYdqgd/xRPk6/kNaXJbIquZ0Kt7FJ9lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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