SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9706d237d5942831b5b1d81b9075333299f0eaf1ef252cbf2f714dfe271bf4d' 
  AND token = 'tl7LFoE25DcppSTiZ8wGUFrm7Avq7bdiEJNHY/bWL1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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