SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0adb205a5a8497ff05a82550acc450276c6abdd760982c53cc2ba4d37db1063c' 
  AND token = 'qFyMP5xdv07sqESXBLPx4+cuBCNvIncoSGye04xpdXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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