SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd6533705085c8c682adeb297e9741922491e91f0effdfb64193b1c401d2cf3' 
  AND token = 'FhpdxsdruCxkb+J0eproseWZUrg3GL3p+hUSgDPoaAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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