SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '955cf35a5517fc6a629ed427ff42934627a00d9e5e08f3264ee88078b34ffce4' 
  AND token = '1ArZz+z9uab/WZBPo9Qb/rKE6jwdzO+VYIH1ENJoR6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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