SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f83801ebdbe96b3cebcf4b8e45930dcb5dd49171927f346afade83309dfbdcb' 
  AND token = '7ALB1LMSKcCa0MMDOp7bKLlpUwPJIRb6vYc70wjLZMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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