SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aaf9b2627c6fcd5d1c84677de81b90efd6f0dfaac003630a346e38456901244' 
  AND token = 'PdhD0fs57o9AvctgfKr1gTaC1NzUzyISwxbaxo+VFF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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