SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b14a1babf5cc16952c081b636058e19fc3c9755a197fd1065deafb1b8db12e5f' 
  AND token = 'c/YYukvNZv2DqzLWHKwZkBi/QWfIHSFemkCq/lOxVCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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