SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8469e7e8e80290495c7c0b3f0eddf099b65000e1fe7572fdc96f8e2345afffe3' 
  AND token = '5R8SW2tflXNricFFxEFWqPoF444IIwzvNuFdl+Ew9RY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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