SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bd8b3a2beb34c686cf46146360a8e05bd5e362e2cf3302fe174d8425831f14e' 
  AND token = 'ENg1NlyIJeQELz813z+B8MS+1FLUK6quKjmDe/xbvEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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