SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7779775bac043fd29025d3cac7d5f08cc02671b11d6a9aa8c46279410636aee' 
  AND token = 'pvJ+lcHL7nVRpeNAe3edosrRd2DI83E1uuNTWR4kiVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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