SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41e89c03add7ed896e35273dac947f4831a2f5b06847b144a774c99ca4aeb1c2' 
  AND token = 'gPq8FwSduKYFBJs6UnfJ2og54zizKpa/3ZXlSrxmxhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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